This prospective, multicenter, observational cohort study will evaluate the efficacy and safety of pegylated interferon alfa (peginterferon alfa) (e.g. Pegasys) plus ribavirin and treatment regimens containing direct-acting antivirals in participants with chronic hepatitis C who are treatment-naïve or treatment-experienced and HIV HCV co-infected. Data will be collected from participants receiving treatment according to current Summary of Product Characteristics (SPC) and local labeling for the duration of their treatment and a 24-week follow-up.